Yahoo on Thursday introduced an upgrade of its platform for building, finding and installing desktop widgets, adding features that the portal hopes will encourage more developers to embrace the Yahoo's take on the mini-applications.

Yahoo Widgets version 4.5 gives developers more options for building the tiny apps. Where Yahoo had limited its construction tools to JavaScript, software builders can now use HTML and Flash. The latter is technology from Adobe Systems that's use to embed multimedia, such as video and audio, into Web applications.

Yahoo also has made it easier for people to download widgets offered on third-party Web sites by releasing a new in-page installer. The technology makes it possible to download a widget in one or two clicks, according to Yahoo.

Widgets are found all over the Web, not just on desktops. The applications are used in online social networks, such as MySpace and Facebook. Yahoo is not alone in also targeting the desktop to lure people to its services. Microsoft and Apple offer similar applications, and Google has its own platform, which it calls Google Gadgets. Services typically provided in widgets include weather forecasts, games, shopping, travel, sport scores, and stock tickers.

For Yahoo, widgets are an element of its strategy to regain some of its former glory as an Internet pioneer. The company lags behind Google in search and online advertising, and has seen its attempts at video and social networking usurped by upstarts MySpace, Facebook, and YouTube, which is owned by Google.

Besides developers, Widgets 4.5 brings new features for consumers. For one, Yahoo has made it easier to find new widgets and those rated the best by users by listing them separately on the widgets home page.

Yahoo also has added features for users to rate and tag widgets, and has made it easier for them to be shared. Yahoo widget fans can now share their favorites over instant messaging or e-mail or through Web sites such as del.icio.us, Digg, and Reddit.

Among the companies using Yahoo's widget platform are Clearspring, Netvibes, and MuseStorm. Clearspring distributes widgets through its clients, which include NBC Universal, Maxim, and Time Magazine. MuseStorm expects to have its applications available through Universal Music Group by the end of the year. Netvibes is offering the widgets it builds to users of its service, which enables people to be their own start pages for the Web.

Yahoo last updated its widgets platform in March. The platform, which runs on Mac OS X and Windows, was originally called Konfabulator, a service developed by Pixoria. Yahoo bought the company in July 2005.